Nosocomial infections account for billions of dollars in hospital costs per year. Candidiasis is a problem of considerable importance in patients undergoing many forms of cancer therapy, including immunosuppression, chemotherapy and heroic surgery. The disseminated form of the disease is also a very common infectious complication in AIDS patients. The diagnosis of disseminated candidiasis remains an enigma for the clinician. Many individuals responding to chemotherapy for cancer will be afflicted with the invasive form of candidiasis. Since the majority of these cases are caused by C. albicans, a normal inhabitant of the gastrointestinal tract of man, we have been analyzing components of mycelial phase (invasive phase) of this organism with respect to their antibody response in patients with invasive disease. In the last 4 years we have identified the antigens from the mycelial phase of this antigenically complex microorganism which appear to be important proteins to which only patients with disseminated disease produce antibodies. We have translated in vitro mRNA of C. albicans and have shown that sera from patients with candidiasis recognize translation products which immunoprecipitate at the same molecular weight as one of these proteins. This will allow us to circumvent the problems inherent in the production of antigenic materials. We have also produced monoclonal and polyclonal antibodies to these proteins. It is believed that these antibodies will be of utmost importance in detecting antigens in patients with malignant diseases, since their antibody response may be diminished because of cancer chemotherapy. The aims of this proposal are: 1) To continue our studies on isolation and characterization of the antigens of C. albicans important in the diagnosis of systemic disease. 2) To use antibodies to these antigens for antigen detection.